import threading
import time

#多线程，回调返回值
class MyThread(threading.Thread):
    def __init__(self,func,args=()):
        super(MyThread,self).__init__()
        self.func = func
        self.args = args

    def run(self):
        self.result = self.func(*self.args)
    def get_result(self):
        try:
            return self.result  # 如果子线程不使用join方法，此处可能会报没有self.result的错误
        except Exception:
            return None

if __name__ == '__main__':
    def foo(a,b,c):
        time.sleep(1)
        return a*2,b*2,c*2

    st = time.time()
    li = []
    for i in range(4):
        t = MyThread(foo,args=(i,i+1,i+2))
        li.append(t)
        t.start()

    for t in li:
        t.join()  # 一定要join，不然主线程比子线程跑的快，会拿不到结果
        print (t.get_result())
    et = time.time()
    print (et - st,end='')
